Traditionally, molded aerated frozen bars are manufactured by partially freezing the ice cream mix, water ice mix or fruit juice mix in conventional batch or continuous ice cream freezers followed by pumping and filling into molds of different shapes and sizes. During the last decade, a new generation of freezers has been developed which are equipped with pre-whippers enabling the mix to be pre-aerated before being partially frozen in the freezer. The molded products are usually quiescently frozen using a cold brine system at -30.degree. to -40.degree. C. If desired, after demoulding, the molded products may be coated with chocolate or compound coating. Finally, the products are usually packaged and stored at about -20.degree. C. until transport and distribution.
This traditional process of manufacturing molded aerated frozen bars has some limitations. For example, the partial freezing of the mix in the freezer, followed by quiescent freezing in the molds, leads to the formation of an icy texture, loss of air, as well as formation of large air cells in the product having a size range of about 110-185 microns (Arbuckle, W. S. Ice Cream, Fourth Edition, 1986. Van Nostrand Reinhold, New York, p234). In addition, shrinkage of the products often becomes an issue. Moreover, when eating the product, a very cold feeling in the mouth is experienced. Furthermore, it is difficult to achieve more than 80% overrun and almost impossible to achieve an overrun of 120% or higher in the finished products using conventional manufacturing. Currently, there is no process that can produce very finely aerated molded frozen bars (having an average air cell size of less than 50 microns) that are smooth in texture, do not suffer from shrinkage, do not give a very cold feeling in the mouth, have a uniform appearance without large air pockets on the surface, as well as having an overrun of 100 to 250%.